Nail-driving apparatus



Feb, 26, 1929. 1,703,458

A. w. RUFF NAIL DRIVING APPARATUS Filed Dec. 51, 1926 5 Sheets-Sheet 1.1 I s N A q I} 51 M if R t i v i '1 N LJ Feb. 26, 1929.

A. W. RUFF NAIL DRIVING APPARATUS Fi led Dec. 51, 1926 5 Sheets-SheetMil Feb. 26, 1929. 1,703,458

A. w. RUFF NAIL DRIVING APPARATUS A. W. RUFF NAIL DRIVING APPARATUSFiled Dec. 31, 1926 5 Sheets-Sheet Fab 2& 1929.. 1,703,458

A. W. RUFF NAIL DRIVING APPARATUS Filed Dec. 31, 1926 5 Sheets-Sheet 5 Sl. I

hvmvm ma mal /6 Br Patented Feb. 26, 1929.

PATENT OFFICE.

AIDNZO W. RUFF, F YORK, PmSYLVANIA.

NAIL-DRIVING APPARATUS.

Application filed December 31, 1926. Serial No. 158,274.

This invention relates to nail driving apparatus. More especially itrelates to apparatus employing a power operated ham- 7 mer as thedriver, and power operated mech- .5 anism for feeding nails as desiredinto position to be struck by such driver.

It is among the objects of the present invention to provide a portablenail driver which can be easily handled by a workman,

which is small enough to be used in restricted spaces, which can bereadily adapted for different sizes of nails ranging from the small tackto the large structural spike, and which operates on the principle ofpower application whereby a number of relatively light blows, varying inquantity to meet the instant conditions, are employed to efi'ect thedriving of the nail. It is a further object to provide feedingmechanism, controlled by the operator, for supplying a single nail asneeded to the driving tool and to provide interlocking mechanism whichprevents the feeding of another nail until the previously fed nail hasbeen driven from the tool. It

is a feature that a nail fed to the driver cannot escape inadvertentlytherefrom or he accidentally driven out'of the tool by an unintentionaloperation of the hammer. Other features reside in the provision of meansfor aligning the the nail initially with the driving axis of the hammerand maintaining such alignment during the driving; in the provision ofmeans for feeding the nails head first to the driving tool, if desired,and

other means for then bringing the nail point first to the work; and inthe provision of means for gathering nails from a mass and deliveringthem to the feeding mechanism.

The apparatus shown in the accompanying drawings is merely illustrativeof the principles involved and it is intended that the patent shallcover by suitable expression in the appended claims, whatever featuresof patentable novelty exist in the invention disclosed.

In the accompanying drawings: v

Figure 1 is an elevation of apparatus en bodying the present invention;

Figure 2 is a plan of the driving tool;

Figure 3 is an elevation, for the most part in medial section on line3-3 of Figure 2 with details of the pneumatic hammer omitted and withthe central portion of the lower part of the handle in section as online 3 a of Figure 9;

Figure 4 is an elevation of the nose end of the tool;

Figure 5 is an elevation in section on line 55 of Figure 3;

Figure 5* is an elevation in section on line 55 of Figure 3;

Figure 6 is an elevation in section on line 6-6 of Figure 3;

Figure 7 is an elevation of the handle end of the tool;

Figure 8 is an elevation like Figure 3, but showing the parts inposition at the end of a driving operation;

Figure 9 is an elevation in section through the handle on line 9--9 ofFigure 3;

F lgure 10 is. a perspective ot the nail jaws;

Figure 11 is an elevation of the nail release mechanism Figure 12 is anelevation partly in medial section of the same on line 12--12 of Figure11;

Figure 13 is an elevation, like Figure 12, with the position of theparts shown when a nail is being fed to the driving tool;

Figures 14, 15 and 16 are diagrammatic representations of the nailselecting cylinders in different positions of operation;

Figure 17 is a section of the nail guide on line 1717 of Figure 12;

Figure 18 is an elevation, in section of the air motor for driving theloader arm;

Figure 19 is an elevation in medial section, of a driving nose adaptedto handle nails fed head first to it;

Figure 20 is an elevation, in section on line 2020 of Figure 19;

Figure 21 is an elevation, in medial sectlon, of the lower portion ofnail release mechanism adapted for feeding a nail head first to thedriving tool; and

Figure 22 is a plan of the nail loading and nail release mechanism.

Referring to the drawings, the apparatus comprises a. power operateddriving tool 10 adapted to be placed by the operator against the work tobe nailed, as for example the metal ceiling 12, and nail releasemechanism 14 which may be conveniently mounted upon a truck 16 when theapparatus as a whole is to be used in different locations. In theapplication of the invention herein illustrated and particularlydescribed the driv lng tool comprises a pneumatic hammer but it iswithin the scope of the invention to employ other power means, forexample, an

of the nail N to be driven.

electrically operated hammer for delivering the blows that are to betransmitted by the driving tool to the nail being driven. A compressedair storage tank 18 and hand pump 20 therefor are mounted on the truckto stpply air for operating the tool 10, the release mechanism 14 and amotor 22 which moves a nail loader arm 24 through a supply of nails inhopper 26. Nails picked up by this arm slide into a nail guide 122connecting the hopper with nail release mechanism 14. The latter as hereshown is also operated by air and under control of the workman may beoperated to select a single nail from the guide and feed it to thedriving tool. In cases where the tool is to be used in a limitedlocality the hopper and nail release mechanism may be permanentlymounted on some fixed support, the. air taken from a pipe line and thenail loader arm driven by an electric motor 28. The

operative connections between such a motor and the loader arm aresuggested by dotted lines in Fig. 1.

Referring now more particularly to the driving tool 10 (see Figs. 2 to10) there is attached to one end of a pneumatic hammer 30 a driving nose32 which is slidable with respect to the barrel 30 of the hammer in anaxial direction. At the other end is a handle 34 by which the toolitself is supported and the apparatus as a whole controlled, there beingin the handle means which enable the operator with one hand to drive anail from the nose into the work and then to reload the tool withanother nail supplied. by the release mechanism 14.

The driving nose has a body piece 36 which has three cylindricalsections 36, 36 and 36 of different external diameters through all ofwhich extends axially a uniform bore 38 slightly larger than the headThe rearmost or largest cylindrical section 36 is externally threaded toreceive an aligning sleeve 40 which extends rearward and nicely fitsaround both a distance collar 42 secured to the end of the hammer barrel30 and the barrel itself. The rear end of the nose body has a recessedbore 38 in which seats a coiled spring 44 that also bottoms on thereduced end 30 of the hammer barrel. This spring tends to keep the noseof the tool extended with the rear flanged end 40 ot' the aligningsleeve pressing against the distance collar 42, but upon the nose beingplaced against the work the force of the spring is overcome by theoperator pushing on the handle and the hammer barrel slides forwardwithin the sleeve until the distance collar brings up against the innerend of the nose body 36.

The intermediate, or second largest cylindrical portion 36 of the nosebody is also threaded to receive a guide sleeve 46 which extends forwardaround the forward or smallest portion 36 of the body, terminating flushwith the forward end of the latter. This sleeve has two diametricallyopposed longitudinal slots 46 into which project a pair of nailcentering jaws 48, (shown most clearly in Fig. 10). Another sleeve 50 isslidable on the forward portion 36 of the nose. body. The inner or rearend of this latter sleeve is machined on opposite sides to formtransverse V-shaped grooves 52 which serve as rocker bearings forsimilarly shaped, inwardly projecting knife edges 54 on the jaws.Forward of the bearings this movable sleeve has slots 50 on oppositesides in register with the slots in the sleeve 46, and similarly locatedon the forward, or smallest portion 36 of the nose body, are two milledgrooves 36, whose flat bottoms serve as the forward bearings for thejaws. The latter are held against the V-shaped bearings at the rear by acoiled spring 56 which is wrapped around the sleeve 50 and rests in asuitable slot 48 in the outer surface of each jaw. Another coiled spring58 similarly arranged tends to hold the forward ends of the jaw againstthe bottoms of the grooves in the nose body portion 36.

The jaws beyond the nose body come together on an axial plane, beingcomplementarily bored to form a hollow conical recess 48 whose axis isin alignment with the axis of the central bore 38 of the nose.

WVhen the tool is not held against the work a spring 60, coiled aboutthe forward portion of the nose body between a shoulder 36. formed bythe intermediate portion, and the slidable sleeve 50, forces the saidsleeve and jaws forward until a beveled surface 48 on each jaw brings upagainst the ends of the slots 46 in the sleeve 46. When thus 0- sitionedthe jaws prevent the escape o a nail fed into the central bore (as willmore particularly hereinafter appear) because they cannot spread beingheld against separation by the slccve 46 engaging the beveled surfaces48.

Assuming a nail to be in the central bore 38 ready to be driven, theoperator places the fiat end of the sleeve 50 against the work at theplace where the nail is to be driven and presses forward on the handle.Spring 60, being relatively weaker than the main nose spring 44,. yieldsfirst allowing the nose body and sleeve 46 to move toward the work. Assoon as the slot end (46) has passed beyond the beveled surface 48, thejaws can then pivot about their knife edge bearings 52 and be spreadagainst the circularly wrapped coiled spring 58 by the nail as it isforced outward between the jaws. The latter however retain a yieldinggrip on the nail shank and thus center it and start it straight into thework and keep it in proper alignment during its penetration.

As the tool is ushed further forward the end of the nose ody section 36comes into contact with a rearwardly projecting ring on the sleeve 50,there y halting the movement of the nose body. spring 44 now yields andthe hammer barrel 30 with its spacing collar 42 slides into the aligningsleeve 40 until a blow transmitting bar 62 brings up against the nailhead. The operator thereupon exerts pressure on the end piece 64 of aplunger valve 64 that projects on the rear side of the handle 34 inposition to be engaged by the operators palm. This valve 64 when heldrearward by its spring 66 closes the main air passage 68 leading fromsupply tube 70 through the handle to the pneumatichammer but when pushedforward its reduced portion 64 registers with the passage 68 and allowsair to flow into the hammer motor.

The hammer at once begins a series of sharp short blows on the bar 62which projects forward from the hammer barrel into i the central bore ofthe driving nose. The blow receiving end 62 of this bar is a cylindricalblock nicely fitting within a bushing 72 secured in the end of thebarrel. This bushing at its forward end is somewhat enlarged, andadjacent its extremity is provided with an internal annular groove 7which retains a spring-washer 74 that engages a beveled face 62 on theenlarged portion of the transmitting bar and limits its forwardmovement. Asillustrated this bar has about an eighth of an inch stroke.The forward end of the bar may be slightly cupped as at 62 to fit ahalf-round or oval headed nail, or may be left flat as desired.

The rapidly recurring light blows on the nail quickly drive it into thework, the handle and hammer barrel following along toward the work. Itis to be noted that the distance between the opposed ends of the spacingcollar 42 and the nose body 86 is the same as the distance between theend of the bar 62 and the forward end of the nose when the latter isretracted. This equality of distances effects a stoppage of the forwardmovement of the handle and hammer when .the nail has been completelydriven into the work.- Sin'mltaneously with the arresting of thisforward movement, the valve mechanism of the hammer operates to stop thelatter from delivering any further blows, even though the plunger valve64 is still pressed inward in open position by the operators hand. 7 1

As the. handle approaches the nose body, a rod 76, slidablelongitudinally along a hole in the top of the handle and over theclamping nut 78 which joins the handle to the hammer, is engaged by thealigning sleeve 40 and pushed backward against the force of v a hair-pinspring 80 which is pocketed in the top of the handle and covered by aplate 82.

The main.

There is at the rear upper edge of the handle in a transverse verticalslot 34 a trigger 84 pivoted at 86 and extending crosswise with itsthumb piece 84" exposed. The operator during the driving keeps his thumbpressed downward on this thumb-piece although he .is unable to move itbecause the upper edge 84 of the trigger (see Fig. 9) on the oppositeside of its pivot, rests against the rod 76. As the latter is pushedbackward, however, by the aligning sleeve'40, a slot 76 on its sidecomes into register with the transverse slot of the handle, thusallowing the trigger to be rotated by the thumb pressure upon it. Thisoccurs, of course, at the end of the driving action, simultaneously withthe extrusion ofthe nail and the stoppage of the hammer as heretoforeexplained. The rocking of the trigger lifts a second plunger valve 88,housed in the handle, against the resistance of spring 90. The body ofthis plunger has a passage 88 with ports 88" and 88 which register, whenthe plunger is thus lifted, with a branch 68 leading from the main airpassage and another branch 92 leading into another bore 92 in thehandle.

The air is therefore transferred from the main passage into this bore 92and thence along a flexible tube 94 to the nail release mechanism 14 foreffecting the delivery of another nail to the driving nose. The movementof the operators thumbs in rocking the trigger, together with thestoppage of the hammer itself, informs him that the driving operation isover and he thereupon removes the tool from the work. The main spring 44and the jaw spring act together to reset all the parts in their extendedposition, except the trigger release rod 76 which is held retractedagainst the hair pin spring 80 until the operator hears or feels theclick caused by the entrance into the nose of the tool of the new nailto be driven. Upon getting this signal he releases his thumb, the

coiled spring 90 moves the plunger valve 88 downward to closed positionand rocks the trigger free from theslot in rod 76 allowing the' latterto be pushed forward by the hair pin spring 80. The tool is now reloadedand ready for the next driving operation.

lVhen the operator rocks the trigger and allows air under pressure toenter the tube 94 it flows to the horizontal arm 96 of the nail releasemechanism, and acts upon a piston valve 98 therein. The 'latter extendsacross the vertical arm 100 and through the end of the horizontal arm,being held by spring 99 against an adjustable seat 102 formed by thetube coupling nut 102, which is threaded into the arm. The air pressureon the piston forces it along its cylinder until its end has uncovered aby-pass104 leading to the passage 106 in the vertical arm. Assuming anail to have been dropped point first into this vertical passage 106 sothat its head is below the by-pass 104 when the latter is uncovered, theair ressure on the nail head will force it along t e delivery tube 108connecting the lower end of the vertical arm with the nail entrance tothe driving tool. The aligning sleeve and the nose body 36 have aninclined hole 38" bored through them into the central bore 38. Into thishole a nipple 110 is threaded and to the latter the delivery tube 108 isconnected by the usual hose couplings. The nail is driven through thistube and nipple into the central bore- 38 and past ball detents 112 tothe closed jaws which arrest its travel.

I The detents 112 prevent its dislodgment from nose but yields readilyto permit the blow transmitting bar 62 to be pushed for ward. Asheretofore explained when the operator hears or feels the characteristicsignal which tells him the nail has. reached the nose he releases thetrigger 84 thus permitting the vertical plunger valve 88 to close theair connection between the main passage- 68 and the air passage 92leading from the handle to the nail release mechanism. In so shifting abeveled portion 88 on the plunger opens the latter passage 92 for escapeof the air through vent holes 34 in the handle. Accordingly the plungervalve 98 of the nail release mechanism is returned to its seat by thenow unbalanced force of its spring 99.

The stem 98 of the plunger projects through a loose fitting nut 97 atthe end of the horizontal arm 96 and is adjustably engaged by a crossarm or extension piece 114 whose upper end connects with two links 116.These latter are also pivotally joined to suitable lugs 118 on twocylinders 120 mounted tangentially to each other at the top of thevertical arm 100. Each of these cylinders has a small half-round groove120 in its outside surface which forms with the opposing groove of theother cylinder a hole somewhat larger than the shank of the nail butsmaller than its head. \Vhcn the plunger valve 98 is seated thepositions of the cylinders are as shown in Fig. 16 with the opposinggrooves opening toward the end of an inclined nail guide 122 down whicha supply of nails has slid under the influence of gravity. lVith thegrooves 120- thus open, the lowest nail on the slide enters the hole ofthe grooves with its head resting on the top edges thereof. As theplunger valve 98 is moved by the air pressure from the driving tool, itsextension piece 114 and links 116 rotate the cylinders through about onethird of a rotation and brings the grooves into the position shown inFig. 14. In this rotative movement the single nail which has entered thehole of the groove is carried forward over the passage 106 in thevertical arm and as the grooves separate, opening outward, the nailslips off the cylinders and by guide plate 124 is directed into the saidvertical passage 106 coming to rest finally on the plunger 98 (see Fig.13). As soon as the latter returns to its seat, however, its transversehole 98 registers with the vertical nail passage 106 and the nailthereupon drops through the plunger and into the delivery tube 108 belowthe by-pass 104. This nail is ready to be fed to the driving nose uponthe next operation of the trigger as already described. In the meantime,the cylinders 120 have again been turned to bring the grooves once morein position to receive the next nail. Only one nail. can be carried bythe cylinders at a time, because the end opening of the nail guide 122is closed by the cylinder walls as the grooves swingaway from theguides.

One of the cylinders is supported by a bracket 126 attached rigidly tothe frame of the nail release mechanism and the other cylinder ismounted on a second bracket 126 which is yieldably supported on thefirst by a clamping bolt 128 and interposed spring 130 holding themtogether. Accordingly the cylinders can handle nails ofvarying thicknesssince the spring 130 can yield and permit the cylinders to separate.Alignment of the cylinder grooves is maintained by guides 131 fastenedon the bracket 126 and engaging ways on the sides of the movable bracket126 The nail guide 122 comprises two strips 122' fastened together onopposite sides of a distance piece 122" at their bottoms (see Fig. 17).It is attached rigidly to the fixed cylinder bracket 126 at its lowerend, and to the nail hopper 26 at its upper end. The hopper hasconverging side walls 26 which cause the nails to slip toward thecentral portion of the bottom. A slot 26" is provided in this portionfor the movement therethrough of the nail loader arm 24. This is similarto the center board of a boat. being pivotally mounted at the junctionof the hopper with the guide. Along one edge of the arm is a slot 24engaged by a roller 134 on the side of a large gear 136. The latter asshown in Figure 1 is oscillated by a rack 138 on the side of a cylinder140 rnovable along a fixed piston 142 (see Fig. 18). The cylinder alsocarries an arm 140 that engages a valve. rod 144 at each end of its upand down strokes and automatically shift-s the plunger valve 146 toadmit air from the supply tanklS to the piston passage 142" against thecylinder head. At the end of the upper stroke the valve is shifted tocut oil the supply and open the piston passage to atmosphere throughvent 148, allowing the weight of the loader arm to cause reverserotation of the gear and a return of the cylinder to its lower position,where again the valve is shifted. Thus the loader arm is moved upwardand downward through the mass of nails in the hop er. Its top edge isslotted at 24" and nails ihlling oint down in this slot are carriedupward y the arm until the inclination of the latter is such that thenails slide from the arm into the slot of the nail guide, and thence tonear the cylinders 120.

It the apparatus is not to be used as a portable equipment, the loaderand guide may be mounted on a fixed support,.and the arm be driven by anelectric motor, as suggested in dot-ted outline in Fig. 1. Likewise theair supply may be taken from a pipe instead of directly from a localstorage tank.

Although the apparatus as heretofore described is adapted for handlingnails of various lengths and sizes, it has been found advantageous indriving very small nails, as for example upholstery or gimp tacks, toconvey the tacks from the release mechanism to the driving nose headfirst. This involves a modification in these two operative elements.

In the nail release mechanism (see Fig. 21) the bottom vertical arm 100is closed by a plug 150 whose inner end is beveled so that a tack Tfalling down the passage 106 will come to rest in a tilted position,with its head just within the entrance of a horizontal exit passage 152from the ver tical arm." The by-pass 104: is continued down through thearm 106 so that its opening into the passage 106 is opposite the lowerside of the exit passage 152. Consequently when the plunger valve 98 isshifted, as heretofore described to admit air to the by pass, this airwill strike the underside of the tack head and push it head first intothe delivery tube 108 connected to the ofi'set arm containing the exitpassage 152.

To properly handle the tack at the driving nose provision must be hadfor getting the tack point first toward the work. cordinglya modifiednose piece 360 is substituted in the aligning sleeve 40 which has asmaller central bore 380 along its axis and a larger transverse hole 154across it near its forward end. Into this latter hole is nicely fittedrotatable cylinder 156 having a bore 156 across it of the same size asthe bore 380. 'As seen in Fig. 19 this bore of the cylinder is verticaland in alignment with the passage through the nipple 159 to which thedelivery tube 108 is connected. A tack cominghead first through thistube enters the cylinder bore 156 and is retained therein by the balldetents 160 which open under the momentum of the tack to let its headpass, but restrain it from falling back into the nipple. Vith a tackthus held, the operator places the nose sleeve 162 against the work andpushes forward on the handle 34. The sleeve 162 of course does not movebut the nose piece 360 slides forward within it, compressing the coiledspring 16 1. Along each side of the nose piece are two slots 360"preferably as Wide as the diameter of the cylinder, and in each slot isa block 166 attached to the sleeve 162. Each block has a vertical slot165 on its face toward the cylinder into which a crank pin 168 in theend of the cylinder projects. As the nose piece and cylinder moveforward, the pins 168 hearing against the sides of the vertical slots165 cause the cylinder to rotate 90 to bring its bore 156 into alignmentwith the bore 880 through the nose piece. When this is done, the rearend of the nose sleeve will have seated against the end of sleeve 40 andfurther movement of the nose piece is prevented. The hammer and handlecan continue to slide forward under the yielding of spring 44, therebyforcing the blow transmitting bar 168 against the head of the tack andpushing the latter forward between the jaws 170. The latter areseparately pivoted in inclined slots 360" at the front of the nose pieceand can be spread against the force of coiled spring 172 to let the tackpass into the work, while keeping a suflicient grip upon the tack toproperly start it. When the tack has been driven, the hammer stops, theoperator presses down the trigger 84 toefi'ect delivery of a new tack inthe nose. Upon removal of the tool from the work the spring 164 forcesthe sleeve forward until a slot 162 on the bottom side brings up againstthe nipple 159 and a similar slot 162 in the upper side engages a screwstud 174. During the forward travel of the sleeve, the cylinder is againrotated 90 bringing its bore opposite the passage through the nipple.

Where apparatus is to be used for handling only one size of nail, theparts can be designed for this particular size, for examplc, a muchsmaller and lighter tool can be made for gimp tacks than would bedesirable for heavy finishing nails. On the other hand, a single toolcan be used. for a considerable range of sizes of nails it being onlynecessary to change the supply of nails or to have several hoppers towhich the release mechanism and guide can be selectively attached tohandle the size of nail desired.

I claim as my invention:

1. Apparatus for driving nails comprising, in combination, a loadingdevice; mechanism connected therewith and adapted to release a nailtherefrom; a driving tool having a handle connected with a supply ofcompressed air and with said release mechanism a nose piece movable onsaid tool with respect to said handle and having a separate connectionwith said release mechanism; and control means on said handle foreffecting connection between said air supply and 'nose of a nailpreviously said release mechanism whereby air is transmitted to thelatter to release a nail from the loading device and feed it throughsaid separate connection to the nose piece; the said control means beingin turn controlled by the relative positions of said nose and handle toprevent feeding of a nail from said release mechanism until said nosepieceis freed of a nail previously fed.

2. Apparatus for driving nails comprising, in combination, nail feedingmechanism; a driving tool having connection therewith and with a sourceof power for operating said tool and said mechanism; control meansassociated with said tool controlling the ap lication of power to saidmechanism for ceding a nail therefrom to said tool; and meansrestraining operation of said control means until a nail previously fedto said tool has been removed therefrom.

3. Apparatus for driving nails comprising, in combination, nail feedingmechanism; a driving tool having a conduit therein connected with asource of power for driving said tool; a second conduit in said toolhaving connection with said feeding mechanism; control means in saidtool adapted to connect said conduits for transmitting power to saidmechanism to effect feeding of a nail to said tool; and a locking devicerestraining said control means from effecting said connection until anail pre viously fed to said tool has been removed therefrom. a

4. Apparatus for driving nails comprising, in combination a driving toolhaving a power operated hammer adapted to strike recurring blows upon anail being driven thereby; a nose on said hammer adapted to be movedwith respect thereto; a handle attached to said hammer having meanscontrolling the operation of the hammer; means for feeding a nail tosaid nose; control means associated with said handle for effectingactuationvof said feeding means; and restraining means on said handlepreventing the operation of the last said control means; the saidrestraining means being released upon a predetermined relative movementbetween said nose and said hammer corresponding with the ejection fromsaid fed thereto.

5. Apparatus for driving nails comprising, in combination, a drivingtool adapted to receive a nail and drive it into the work to be nailedhaving a member relatively movable with respect to the tool; means forfeeding a nail to said tool comprising a supply of nails and mechanismfor releasing a nail from said supply; control means associated withsaid tool and arranged'to be actuated by the operator for effectingoperation of the release mechanism; means restraining the operation ofsaid control means; the said restraining means being released uponrelative movement of said member a predetermined distance.

6. Apparatus for driving nails comprising, in combination, a poweroperated driving tool having parts relatively movable; means forsupplying nails thereto comprising, a hopper; a nail guide arranged torecelve nails from the hopper; releasing mechanism adapted to release asingle nail from said guide; a conduit connecting said release mechanismwith the tool for conducting the said single nail thence; there beingcontrol means associated with the driving tool controlling the operationof said releasing mechanism and comprising a restraining element adaptedto be freed to permit actuation of the control means when the relativelymovable parts of said tool are moved to a predetermined relation withone an-- other. I

7. Apparatus for driving nails com rising, in combination, apower-operated riving tool; means for feeding a nail thereto including aconduit leading to the driving tool; release mechanism connected withsaid conduit having a plunger valve controlling a nail passage to saidconduit; control means associated with the driving tool for effectingmovement of'said. valve to admit a pressure force to said conduit forforcing the. nail therealong to the driving tool; and means forreturning said valve upon release of the pressure force to permitanother nail to pass from the release mechanism into the conduit.

8. Apparatus for driving nails comprising, in combination, apower-operated driving tool; means for feeding a nail thereto includinga conduit leading to the driving tool; release mechanism connected withsaid conduit'havingmeans for selecting a single nail from a supply anddelivering it to a nail passage in said release mechanism leading tosaid conduit a second passage in said release mechanism connecting saidnail passage with a source of pressure force; a valve controlling bothsaid passages and having operative connection with said selecting meansand control means associated with the driving tool for admitting forceto said second passage whereby the valve is moved to admit the force tothe nail passage and conduit to feed the nail to the driving tool, andto effect operation of the selecting means; there being power storagemeans for returning the valve to its initial position upon the controlmechanism shutting off the pressure force acting upon the valve.

9. Apparatus for driving nails comprising, in combination, a pneumaticdriving tool adapted to strike recurring blows upon nail feedingmechanism having one conneca ing, in combination, nail fe tion with saidtool for transmission of air therefrom and having another connection fordelivery of a nail thereto; valve means in said 'tool for admitting airfrom the supply to the air transmitting connection; a valve in therelease mechanism normally separating the last mentioned connection andthe nail delivery connectionbut adapted to be moved by said air to joinsaid connections whereb the .nail is fed to the tool'; and means orfeeding the nail into said delivery connection prior to the movement ofsaid valve.

10. Apparatusfor drivin nails comprising mechanism; a driving toolhaving connection therewith and with a source of power for operatingsaid tool and said mechanism, and comprising a movable nose piece;control means associated with said tool controlling the application ofpower to said mechanism for feeding a nail therefrom to said tool; andmeans restraining operation of said control means until said nose piecehas moved a predetermined distance.

11. Apparatus for drivin nails comprising, in combination, nail feedingmechanism;

a driving tool having a handle connected with a source of power foroperating said tool and said mechanism; a movable. nose piece on saidtool having connection with said feeding mechanism; control meansassociated with said handle for controlling the application of saidpower to said mechanism for feeding a nail therefrom to said nose piece;and restraining means operatively connected with said nose piece andactuated by movement thereof, normally restraining operation of thecontrol means until said nose piece has moved a predetermined distance.

In testimony this 30th day Pennsylvania.

whereof I afiix my signature of December, 1926, at York,

ALONZO W. RUFF.

